Project summary 11/15/2002:

Lake Como is a 140-year old, 98-acre impoundment of Duncan Creek located in the City of Bloomer, Chippewa County, Wisconsin.  It is a mostly urbanized, shallow and fertile body of water situated in a large and agriculturally dominated watershed.  The lake is recognized as an important natural resource for the community, and is considered a regional asset of environmental, recreational and economic significance.  Lake Como is known and used primarily for fishing, peaceful relaxation, wildlife and scenic enjoyment, and limited boating opportunities.

Recently, the lake’s value has been limited by problems such as degrading water quality, excessive sedimentation, nuisance aquatic weed and algae growth, declining fishery habitat, and restricted boat accessibility, among others.  These problems have prompted the community to take actions that will restore the natural, economic and social values for the continued benefit of the greatest number of public citizens.

The City of Bloomer desires to restore the lake bathymetry to approximate it’s original contour.  This will entail the repositioning of soils on the lake bottom and the removal of the excess foreign material that has accumulated over 140 years.  Sediment traps will be installed and maintained in the upper reaches of the lake where feeder streams enter.

The Bloomer Community Lake Association has mapped the current and original bottom contours of the lake to a precision of 1/10 foot vertical in a grid of 50 foot or less intervals.  Studies indicate approximately 250,000 cubic yards of foreign material has been deposited over the original lake bottom.

Alternate ‘A’ calls for the restoration to be done during the winter of 2003 – 2004 using mechanical methods while the lake has been drained to facilitate the reconstruction of the Bloomer Mill Dam.  Bulldozers and excavators with high flotation tracks and mats will be used to establish desired contours to the bottom.  Excess material will be transported by truck to a disposal site less than 2.5 miles away.

Alternate ‘B’ calls for the restoration to be done during the summer/fall of 2004 using a floating hydraulic cutter head dredge when the lake is at normal full pool elevation.  The slurry would be pumped to the same disposal site described below.  WPDES permits, monitoring  and dewatering wells, settling and containment  ponds will  need to be designed, priced and included in this project alternate.

The design for Alternate A is nearly complete.  Alternate B is offered with the expectation it will include additional costs upfront for design, permitting, ground water monitoring, etc.,  but may provide lower material transport expenses.  Bidders of Alternate B must include these costs and procedures to allow the City to evaluate total completed project costs using either method.

The disposal site is an industrial park vacant lot of approximately 13 acres that is in need of up to 300,000 cubic yards of fill to be at grade with surrounding lands.  It is a gently sloping area with sandy soils and a thin water table located approximately 14 feet below the existing surface.  A compacted soil berm with multiple erosion control measures will contain and stabilize the spoils that are deposited, spread and compacted upon the site.  Since the volume of water leaching into the surface or draining from the area using Alternate ‘A’ is small and free from contaminates, it is expected that a WPDES wastewater permit will not be required.

The proposed disposal site sits adjacent to land that was recently considered as a site for a public school.  The school district contracted to have soil borings and testing done as part of their feasibility study.  All 15 boring samples, including two that are less than 50 feet from the edge of the proposed disposal site, indicate sandy soils, an absence of any hazardous materials and a thin water table 12.5 to 16.0 feet below the surface.

The sediment has been sampled and analyzed.  Boring sites were chosen with the consultation and assistance of WDNR and City personnel in an effort to select locations that would be most likely to contain hazardous substances.  Testing as described by NR 149 indicated no defined hazardous materials were present in quantities that would require the material be treated as ‘hazardous waste’.  It is mostly organic matter, averaging 45% solids that are finer than a #200 sieve.  It is the desire of the Owner to remove as much of this material as feasible.